Develop Reference

In Windows Forms what's the easiest way to get the control(s) over which another control is placed?

I'm not interesting in finding the parent control. I'm interested in finding a reference to the control or controls on top of which a given control is placed.

Rectangle.Contains
if (control1.Bounds.Contains(control2.Bounds))
{
//control1 contains control 2.
}
You can use this logic to find reference of control or controls on top of which a given control is placed.

How do I create a Tab Control with no Tab Header in Windows form?

I have created a Windows form using a Tab Control, but it has a header with it. I want to hide it. I am not able to do it using any properties of the Tab Control. Is there any property defined for hiding the tab header for the Tab Control without going through the code?

Use following code to hide the tabs or set these properties in design.
tabControl.Appearance = TabAppearance.FlatButtons;
tabControl.ItemSize = new Size(0, 1);
tabControl.SizeMode = TabSizeMode.Fixed;

You want the tab panels without the feature allowing a user to switch between them, so I suppose you want to create few separate sets of controls to be shown to the user one at a time. You can achieve this in several ways (you can choose one of them if you find it appropriate in your case):
Use several Panel controls instead of several tabs in the TabControl, however, it would be hard to work in the designer, because all the controls would be visible
Use different Forms instead of tabs to keep the layout parts separated. It can be ok, but you may not want to use multiple Forms, so it depends on a specific case.
and finally, the suggested solution:
Encapsulate each set of controls in a UserControl. This allows you to keep each layout separately, so you can easily design each of them without the other controls getting in the way ;). The the code handling each of the layouts would also be separated. Then just drag those controls in the Form and use set their visibilities appropriately to show the one you want.
If none of those suggestions work for you, let me know, so I can look for other possible solutions.

It's more easy as you think, you just drag the panel's window upper, so will be outside of the form.

Use DrawMode: OwnerDrawFixed will hide TabPage header text DrawMode : OwnerDrawFixed

Another way to achieve the same (or similar) is: You can remove tabs from TabControl.TabPages collection and then add the tab you want to show.
During the Form initialization I remove tabs (so into the designer I can easily manage them) and in some control event (as button click) I show the tab the user has to see.
Something like that:
// During form load:
ctrTab.TabPages.Clear();
// ......
// During button click or some other event:
if(rbSend.Checked)
ctrTab.TabPages.Add(pgSend);
else
ctrTab.TabPages.Add(pgReceive);
In this way the user can still see the header tab but just as title of controls group, he can't change/switch the current active tab.

Change C# user control layout in windows forms development

I have a user control that contains multiple controls (CheckBox, Button, Label...).
I want to change the layout of this user control to support right to left languages but i can't find how to do it.
Currently i can change the controls alignement using the RightToLeft property. But how can i change their positions?
Thank you for your time.

Thank you guys for your answers but there is a better way to do it.
First we go to the user control properties and select the language property.
After changing it to another language a new resource file will be created for the user control.
After that, using the designer we can change the controls positions in the user control as we like.
The new values will be saved in the created resource file.
When the language has changed, the corresponding resource file will be loaded and the positions will be changed.
If the language is a right to left one, don't forget to specify the right to left property for the controls.
Hope this helps.

Use the layout controls with the RightToLeft property and follow the following links for implementation:
RightToLeft property in Form in C#
http://msdn.microsoft.com/en-us/library/system.windows.forms.form.righttoleftlayout(vs.80).aspx:
Developing Arabic applications should be easy!
Implementing Mirror-Aware Controls for Windows Application with Visual Studio .NET

Try to use FlowLayoutPanel or TableLayoutPanel to hold your controls and change panels RightToLeft property

User control mirroring is not supported for user controls, see this connect article: http://connect.microsoft.com/VisualStudio/feedback/details/121202/usercontrol-mirroring-is-not-inherited-from-the-form
Their suggested workaround is to use a table layout panel which will mirror the controls in right to left.

Access sub-controls of custom control from code

I created a custom control in Expression Blend which consists of multiple TextBlocks placed in a Grid. Now I added this custom control to my phone page in Visual Studio and want to access and change the text of these TextBlocks from C# code.
How do I access these sub-controls in code?
I thought I could do something like this:
MyCustomControl.TextBlock1.Text = "New Text";
But it's not that easy. So how do I do it?

The property MyCustomControl.TextBlock1 exists but is internal, not public. You can use MyCustomControl.FindName("TextBlock1") as TextBlock to locate the resources by name instead.

Does GetTemplateChild(string name); work ? You should be able to use it, to access the elements of your control's template

Try below code both should work for your requirement:
Control subControl1 = (Control)MyCustomControl.Controls[0];
or
TextBox subControl1 = (TextBox)MyCustomControl.Controls[0];
Using any code you are able to access Text Property.
Always keep remember the hierarchy in your custom control and then try to access all control level-by-level.
If still you are facing any issue feel free to ask.

adding a windows form object to listbox

I'm creating a twitter client in C#.
I want to put every tweet as an element of a listbox.
I created a windows form that represents a tweet(it has a picture, and labels).
My problem is that when i can't see the tweets when i add them to the listbox. After adding 3 tweets(windows form objects), the listbox has 3 blank elements in them, but i can't see anything of it.
How can i add a windows form object to a listbox?
(these forms are working fine, because i can see them if i use the ShowDialog method)
please help

You can add a Form object to the ListBox.Items collection but the only thing you'll ever see is the type name of the form. ListBox is not capable of rendering controls as its items.
The efficient solution is to implement the ListBox.DrawItem event and custom draw the tweet. There's a good example of such an event handler in the MSDN Library documentation for the event.
The slow solution is to add controls to a Panel's Collection property with its AutoScroll property set to true. That cannot be a form, it must be a UserControl.

You may want to look into implementing it using WPF. Where you can pretty much put anything inside a listbox.

Some thoughts:
You'd do better to work with custom controls, rather than a whole form
A listbox can't have controls on it... consider a ListView: http://www.codeproject.com/KB/list/ListViewEmbeddedControls.aspx
Some example code of what you're trying will help us zoom in on what you're doing
HTH,
James

I don't think ListBox can display anything but a text string for each element, so you won't be able to see an image of each form if that's what you were hoping for. You might try using FlowLayoutPanel instead to manage a list of controls.